Transport containers for radioactive materials

ABSTRACT

A container for the transportation of radioactive material, specifically, irradiated fuel elements. The transport container consists of an outer shock resistant steel container and an interfitted inner container constructed of a plurality of radioactive shielding inserts.

United States Patent 1 1 3,575,601

[72] Inventors Graham Eades Lindsay [56] 'ReterencesCited "W Dim; UNITED STATES PATENTS k t' f 'g g 2,935,616 5/1960 Smith,Jr. e161. 250/108 3,046,403 7/1962 Montgomery.... 250/106(S) 2%- 23 3,111,586 11/1963 Rogers 250/103 3,113,215 12/1963 Allen 250/108 g i g May 3,119,933 1/1964 Allen 250/108 [45] Patented 1, 3,310,676 3/1967 Haram,.lr 250/43.5x

9 [73] Assignee United Kingdom Atomic Energy Authority i a y Examiner-Archie R. Borchelt London, England AttorneyLarson, Taylor and Hinds [54] TRANSPORT CONTAINERS FOR RADIOACTIVE MATERIALS 4 Claims, 3 Drawing Figs. [52] U.S. Cl. 250/108, ABSTRACT: A container for the transportation of radioactive 250/106 material, specifically, irradiated fuel elements. The transport [51] Int. Cl G2lf 1/00 container consists of an outer shock resistant steel container [50] Field of Search 250/106, and an interfitted inner container constructed of a plurality of 108 radioactive shielding inserts.

6 &9 I I I I I i 2 I 7 PATENTED APR20197| 335751301 SHEET 2 OF 2 INVENTORS GRAHAM E. LINDSAY LESLIE S. EVANS ATTORNEYS 1. TRANSPORT CONTAINERS FOR RADIOACTIVE MATERIALS This application is a continuation of our previous application, Ser. No. 548,255, filed Mayv 6, 1966, now abandoned.

This invention relates to containers for the carriage of radioactive materials and is particularly but not exclusively concerned with containers for transporting irradiated nuclear fuel elements.

An irradiated fuel element transport container is required to comply with international regulations covering the transportation of radioactive materials. The regulations govern the provision of biological shielding, permitted radiation levels and acceptable internal and external temperatures and require that the container shall withstand a defined maximum transport accident, for example a container must be capable of withstanding a free drop test from 30 feet 'followed additionally by a fire test at 800 C. for 30 minut'es without damage sufficiently severe to cause a release of contents or a significant reduction in shielding.

Known forms of transport container, generally of steel, cast iron and lead construction have been specifically designed for particular fonns of fuel element with the result that a multiplicity of noninterchangeable containers are available. The noninterchangeability of the containers leads to duplication of transport facilities special support and. handling arrangements etc. with resultant increases in cost.

One object of the present invention is to provide a container for the transportation of radioactive materials in which the possibility of accidental release of the contents of the container is minimized and a further object of the invention is to provide a container particularly suitable for the transportation of a variety of radioactive materials.

According to the invention a container forthe transportation of radioactive material hemretically scalable vessel of impact resistant construction, internals for said vessel formed from dense radiation shielding material and means associated with said internals to shieldably locate said radioactive material.

Preferably the vemel has the form of a thick walled high pressure drum and the internals comprise -a plurality of shielding inserts arranged to enclose a central load receiving space. The inserts may be provided with locating pockets for the material being carried or alternatively a separate basket can be used to position the radioactive material relative to the shielding inserts. In one form the vessel is circular in cross section and is provided with dished ends.

The vessel may include a wall extension portion adapted for insertion between the body of the vessel and a removable lid or top portion to accommodate long length loads.

In one form the vessel is provided with external heat transfer fins and a number of said fins extend to the base of the vessel to form vessel support members.

To enable the nature of the invention to be more readily understood embodiments of the invention will now be described by way of example only with reference to the accompanying drawings. In the drawings:

FIG. I is a sectional elevation of a transport container for irradiated nuclear fuel elements;

FIG. 2 is a sectional plan on the line II-Il of FIG. 1; an

FIG. 3 is a sectional elevation of a container similar to that of FIG. I but showing an extension portion.

Referring to FIG. I and FIG. 2 of the drawings a container for irradiated fuel elements comprises a thick steel outer vessel 1 into which can be inserted cast iron shielding members arranged to suit the dimensions of the fuel elements being transported.

The vessel is fabricated from steel plates approximately 5.5 inches thick. The top and bottom are ellipsoidal, the top comprising a full diameter lid 3 removably secured to the body of the container by a plurality of bolts 4 located in recesses 5 formed in the lid. The lid is spigotted to the body and joint rings 6 interposed between the lid and the body ensures leak comprises a ti htness. I

e container, approximately 5 feet in diameter, IS provided cast iron shielding members l0, l1 and 12. Members 10 and 11 form the top and bottom of an inner container and are spigotted to a substantially annularmember 12. Member 12 is apertured to provide locating positions I3 for irradiated nuclear fuel elements. For ease of handling the shielding member 10 may be attached to and removable with the lid.

FIG. 3 shows a modification to the container whereby the fuel elements having a length greater than normal can be accommodated within the container. The container is extended by inserting an annular extension portion 14 between the lid and the container body. Extension portion 14 is provided with mating faces corresponding to the joint surface on the lid and body, and is secured in position by the use of long lid clamping bolts 15. The internal shielding container is also extended by the insertion of a further annular member 16.

It will be appreciated that the shielding blocks 12 and 16 need not be provided with pockets for the location of the fuel' elements. The elements may be positioned in a separate basket (not shown) insertable in a central aperture provided in the said blocks. Such an arrangement provides great flexibility in the dimensions and number of fuel elements that can be accommodated.

The internal shielding need not fill all the internal shielding space ,within'the steel container, for example where shielding conditions permit a thinner section inner container of material or construction to meet a particular requirement can be used and the inner shielding members spaced from the outer wall by suitable struts The struts may be of a light weight material to reduce the total weight of the container in this instance. The struts also act as heat transfer paths between the internal shielding and the outer container.

It will be apparent that the transport container described is particularly advantageous in the ease by which a variety of active materials can be accommodated in a single construction of basic outer container by replacing or rearranging the internal shielding members to provide the desired degree of shielding for the specific load.

We claim:

I. A container for transportation of radioactive material comprising an impact resistent outer vessel constructed from a plurality. of parts, interlitting to define a hermetically sealable chamber, an inner container, the outer surfaces of which conform to the inner surfaces of the outer vessel, said inner container removably located in said chamber, said inner container constructed of a plurality of radioactive shielding inserts interfitting to define a second closable chamber therein, said inserts being interchangeable with similar inserts such that the dimensions of said second chamber may be selectively varied to accommodate different shapes and sizes of said material without necessarily adjusting the dimensions of the outer vessel.

2. A container according to claim 1, wherein the outer vessel comprises a body portion, a removable lid and a wall extension portion adapted for insertion between said body portion and said lid to accommodate long length loads.

3. A container according to claim I, wherein the inserts are provided with locating pockets for the material being carried.

4. A container according to claim 3, wherein the vessel is provided with external heat transfer fins and a number of said fins extend to the base of the outer vessel to form vessel support members. 

1. A container for transportation of radioactive material comprising an impact resistent outer vessel constructed from a plurality of parts, interfitting to define a hermetically sealable chamber, an inner container, the outer surfaces of which conform to the inner surfaces of the outer vessel, said inner container removably located in said chamber, said inner container constructed of a plurality of radioactive shielding inserts interfitting to define a second closable chamber therein, said inserts being interchangeable with similar inserts such that the dimensions of said second chamber may be selectively varied to accommodate different shapes and sizes of said material without necessarily adjusting the dimensions of the outer vessel.
 2. A container according to claim 1, wherein the outer vessel comprises a body portion, a removable lid and a wall extension portion adapted for insertion between said body portion and said lid to accommodate long length loads.
 3. A container according to claim 1, wherein the inserts are provided with locating pockets for the material being carried.
 4. A container according to claim 3, wherein the vessel is provided with external heat transfer fins and a number of said fins extend to the base of the outer vessel to form vessel support members. 